Servosystem control unit for antenna rotators



1958 J. P. CHADOWSKI ETAL 2,861,235

SERVOSYSTEM CONTROL UNIT FOR ANTENNA ROTATORS 5 Sheets-Sheet 1 FiledJune 22, 1954 FIG. I

INVENTORS JOSEPH P CHADOWSK/ B! & ANTHONY 6. TURK A T TORNE Y5 Nov. 18,1958 J. P. CHADOWSKI ETAL 2,861,235

SERVOSYSTEM CONTROL UNIT FOR ANTENNA ROTATORS Filed June 22, 1954 5Sheets-Sheet 2 INVENTORS 3 JOSEPH P CHADOWSK/ y 8 ANTHONY G. TURK ATTORNE Y5 1958 J. P. CHADOWSKI ETAL 2,86

SERVOSYSTEM CONTROL UNIT FOR ANTENNA ROTATORS Filed June 22, 1954 3Sheets-Sheet 3 INVENTORS JOSEPH P CHADOWSK/ 8 ANTHONY G. TURK ULMMWATTORNEYS United States Patent SERVOSYSTEM CONTRDL UNIT FOR ANTENNAROTATORS Joseph 'P. Chadowski, Brooklyn, and Anthony G. Turk, Cleveland,Ohio, assignors to Cornell Dubilier Electric Corporation, SouthPlainfield, N. 3., a corporation of Delaware Application June 22 1954,Serial No. 438,559

'3 Claims. .(Cl. 318-311) I The present invention relates in general to'a selector control unit for antenna rotators, and more particularly is"mounted on a motor-driven rotator so that the antenna may be rotated byremote control to any desired direction. The control unit employedgenerally. consists of a switch for closing the motor circuit, andindicating means for showing the position of the antenna. In somecontrol units two switches are used so that a reversal of totation maybe obtained. The switch is closed to actuate the r'otator, and it isopened by the operator when the indicator shows that the antenna hasreached the desired position of directional orientation or angularity. v

it is a primary object of our invention to provide a control unit of thecharacter described with which a rotator may be actuated to rotate theantenna to a pre-selected position of angularity.

Another object of our invention is to provide a control unit which isautomatic in operation, that is, which requires no supervision ormanipulation by the operator other than the pre-selection of theposition to which the antenna is to be rotated.

A further object of our invention is to provide a control unit providedwith energy accumulator means for maintaining said unit in operation inresponse to initial manipulation thereof.

Still another object of our invention is to provide a control unithaving readily accessible means for effecting adjustment orsynchronization thereof.

Other objects and advantages of my invention will be apparent during thecourse of the following description.

In the accompanying drawings forming a part of this specification and inwhich like numerals are employed to designate like parts throughout thesame,

Fig. 1 is a front elevation of a control unit embodying the featuresofour invention, taken in the direction indicated by line 1-1 of Fig. 2,and portions thereof being broken away to reveal details.

Fig. 2 is a longitudinal cross-sectional view taken on line 2-2 of Fig.1.

Fig. 3 is a fragmentary sectional view taken on line 33 of Fig. 2 andshowing details of the selector assembly.

Fig. 4 is a fragmentary cross-sectional view taken on line 44 of Fig. 2and showing details of the energy accumulator assembly.

Fig. 5 is a plan view of a portion of a remote servomotor assembly orantenna rotator showing the pulsing switchsassembly.

Fig. 6 is a fragmentary cross-sectional view taken on line 6-6 of Fig. land showing details of the escapement assembly.

Fig. 7 is a schematic wiring diagram showing the electrical connectionsbetween the various components of the control system.

Referring more particularly to Figs. 1-6 of the drawings, We have shownan automatic control unit which is housed or contained in an ornamentalcasing 10, which may be of molded plastic resin or the like, and whichis mounted on rubber supports 11. The elements 11 are secured to thecasing 10 by screws 12 which extend through the bottom of the casing 10and threadedly engage a base plate 13. The screws 12 also serve tosecure the casing to the base plate 13.

Mounted on the rear of the chassis or base plate 13 is a conventionalterminal strip 14 which, in this instance, is provided with fourterminals 15. The terminal strip 1'4 is secured to a bracket 16 whichalso is traversed by a conventional plug-in type of power cord 17. Thebracket is welded to thebase plate 13. Access to the terminals 15 may behad through a suitable aperture 18 which is provided in the casing 11).

Also mounted on the chassis 13 is a step-down transformer 19 and acondenser 20. For clarity of detail, we have not shown the variousconnecting wires in the views of the parts, these connections beingshown in the wiring diagram of Fig. 7 where they will be clearlyunderstood by those skilled in the art.

The remainder of the operating elements of the control unit are bestdescribed by considering the principal sub-assemblies individually.These sub-ase'mblies may be functionally defined as follows:

(a) A selector assembly 21,

(b) An energy accumulator assembly 22, (0) An escapement assembly 23,and (d) A pulsing switch assembly 24.

The selector assembly As best seen in Figs. 2 and 3 of the drawings, theselector assembly 21 includes a shaft 25 which is rotatably journalledbetween spaced front and rear plates 26 and 27 respectively. The frontplate 26 is provided with a flange 28 which rests upon base plate 13 andis secured thereto by threaded fasteners 29. The rear plate 27 issecured to the front plate 26 by means of spacer posts 30 and screws 31.

A selector wheel '32, of insulating material, is fixedly secured toshaft 25' for rotation therewith. The periphery of the wheel 32 isprovided with a series of circumferentially-spaced detent notches 33which, in this particular embodiment, are uniformly spaced 6 from eachother thus providing a total of 60 such notches in the 360 ofcircumference.

Secured to wheel 32 on the opposite faces thereof, as by rivets 34, area pair of commutator discs 35, 36 which are electrically insulated fromeach other. The disc 35 has electrical connection to one blade 38 of aswitch 37,

the other blade 39 of the switch being in electrical contact with thedisc 36. Both blades 38, 39 are fixedly secured to the selector wheel32, however, the switch blade 38 is flexible or resilient so that it canbe moved horizontally away from switch blade 39 to effect opening of theswitch 37.

That portion of the wheel 32 which is diametrically opposite the switch37 has fixedly secured thereto, as by rivets 43, a pair of contact arms40, 41, each of which has a horizontally extending leg 42. Each of thelegs 42 lies adjacent an opposed side of a horizontally extendingembossment or projection 44 on wheel 32. The projection 44 serves toseparate one contact arm from the other, so that the arms 40, 41 areelectrically insulated from each other. Another function of theprojection 44, is to brace or reinforce the contact legs 42 so that theywill not fiex or bend during the operation of the control unit, to bedescribed hereinafter. A portion of the shaft 25 is bored out as at 45and recessed as at 46 to provide a convenient conduit for lead wire 47which connects to contact arm 40, and lead wire 48 which connects tocontact arm 41. Both lead wires are connected to the terminal strip 14,as shown in Fig. 7. The contact arms 40, 41 are circuit elements of alowvoltage control circuit, and the switch 37 is an element of a powercircuit, as will appear more fully hereinafter.

As best seen in Fig. 1, the selector assembly 21 also includes a pair ofPhosphor bronze leaf brushes 49 which are secured in horizontally spacedrelationship on an insulating block 50 which is mounted on the rearplate 27 "in a position to cause each of the brushes to have wipingelectrical contact with one of the commutator discs 35, 36. The block 50also supports a resilient arm or leaf spring 51 which carries a detentball 52 on its free end. The ball 52 is adapted to yieldably engage thenotched edge of the selector wheel 32 to restrain its movement. Thebrushes 49 are connected by suitable leads to the power cord 17, throughthe primary coil of the transformer 19 as an element of the circuit.

The energy accumulator assembly As best shown in Figs. 2 and 4, theenergy accumulator assembly 22 includes a toothed follower gear 53 whichis rotatably mounted on shaft 25 in operative engagement with theselector assembly 21. The gear 53 may be maintained against axialdisplacement by suitable means such as a snap-ring 54 which is securedin an annular recess on shaft 25.

The gear 53 is provided with an axially offset marginal projection 55 inwhich is threadedly received a co-axially extending camming screw 56.The cam element 56 is adapted to engage and displace the switch blade 38axially so as to open the switch 37. This displacement will only occurwhen cam 56 and blade 38 are directly opposite each other or in phase. Ahairpin spring 57 serves to prevent vibratory loosening of screw 56while at the same time permitting adjustment of the screw whenevernecessary.

Rotatably mounted on the hub of the gear 53, as on sleeve bearing 58, isan open-faced cylindrical casing or drum 59 containing a spirally-coiledflat spring or torsion spring 60 having the outer end thereof anchoredto the drum as at 61 and having the inner end thereof anchored as at 62to any one of several projections 63 which are provided on a drum cover64. The cover 64 is also rotatably mounted on the sleeve bearing 58.

The cover 64 is provided with a contact arm 65 and the drum 59 isprovided with a similar arm 66. In assembling the device, the cover 64is rotated relatively to the drum 59 in order to pre-energize the spring60 and thus establish an initial torque relationship between the coverand drum. The cover 64 would be urged to rotate counterclockwise (Fig.4) and the drum 59 would be urged to rotate clockwise. However, the gear53 is provided with a projection 67 which is disposed in the path ofmovement of the contact arms 65-66 and prevents such relative rotationbetween the drum and the cover. The projection 67 maintains the arms65-66 in parallel spaced relationship and defines a space between thearms which is of sufiicient width to accommodate the projection 44 andthe opposed legs 4-2 of contact arms 40, 41 of selector wheel 32, whileallowing a small clearance space 68 to either side thereof. It will beunderstood that projection 67 is diametrically opposite the cam screw 56so that the projections 44 and 67 will assume the positions shown inFig. 4 when the screw 56 is directly opposite switch blade 38.

Both arms 65 and 66 are electrically grounded, and

one side of the transformer 19 secondary is grounded as shown.

The escapement assembly As shown in Figs. 1 and 6, the escapementassembly 23 includes an escapement wheel 69 which is rotatably mountedon a stub shaft 7 0 which is secured between the front and rear plates26, 27. Disposed on opposite sides of the wheel 69 and integratedtherewith are gears 71 and 72. The gear 71 is in engagement with thefollower gear 53 and is actuated thereby. The gear 72 engages a pointergear 73 which is rotatably secured to shaft 25 adjacent the exterior offront plate 26. The gear 73 carries a finger or pointer 74 which isfrictionally secured thereto and which overlies a transparent dial'75which will be more fully described hereinafter.

The escape wheel 69 is provided with a series of uniformly spacedcircumferential notches 76, in this instance there being twelve of suchnotches. The wheel 69 is normally prevented from rotating by a pawlassembly 77 which is pivotally secured to the front plate 26 by means ofa stud or post 78. The assembly 77 includes a rocker arm or lever 79which is pivotally movable about the axis of post 78, rearwardly of thewheel 69, and is provided with spaced apertures or slots 80 and anextension or finger 81 which projects through the base plate 13 so as tobe accessible from the underside of the control unit. Also pivotallymounted on post 78 are a pair of pawls 82, 83 which are adapted toselectively engage the notches 76 and secure or lock the wheel 69against rotation, thus also preventing rotation of the follower gear 53.

Each of the pawls 82, 83 is provided with a lateral extension 84 whichtraverses one of the apertures or slots 80 in arm 79. A coil spring 85is connected across the pawls 82, 83 to urge them toward each other.This arrangement provides a yieldable or resilient lost-motionconnection between the pawls and the rocker lever 79. The lever 79 alsois yieldably maintained in the position shown in Fig. 1, by means of acoil spring 86 which is anchored to a bracket 87 on the front plate 26.

A link 88 is pivotally secured to the arm 79, as at 89, and the otherend thereof is operatively connected to the movable core or plunger 90of a solenoid 91 which is secured to the rear plate 27 so as to lieintermediate the front and rear plates 26, 27.

In response to energization of the solenoid 91, the

causing the arm 79 to pivot counter-clockwise. This pivotal movementbrings the lower pawl 82 into springloaded engagement with the edge orperiphery of the escape wheel 69 intermediate two of the notches 76.Further pivotal movement of the arm 79 causes the upper pawl 83 to bedisengaged from the notch in wheel 69. The wheel 69 will then rotate inresponse to the torque impressed upon it by torsion spring 60 throughthe gear 53. Its direction of rotation will depend upon the direction ofrotation of gear 53. The wheel will then rotate until the pawl 82engages a notch 76 and thus locks the wheel 69 against -furtherrotation. When the solenoid 91 is deenergized, the spring 86 causesrocker arm 79 to pivot clockwise and pawl 83 will engage the peripheryof wheel 69. Further rotation of arm 79 causes disengagement of thelower pawl 82 and the wheel 69 will continue its interrupted rotationuntil pawl 83 engages a notch 76. During this cycle of movement of therocker arm assembly 77, the escape wheel has rotated a total of 30,equal to the angularity between adjacent notches 76. By means of thegear ratios established between follower gear 53 and gear 71, andlikewise between gear 72 and pointer gear 73, the 30 rotation of escapeWheel 69 corresponds to 6 of rotation of follower gear 53 and pointergear 73 and selector wheel 32. The 30 rotation of the wheel 69 alsocorresponds to one pulsation or energization of the 9lenoid 91 inresponse to 6 rotation of an antenna to overlie the dial 75.

structure by means of a pulsing switch assembly which will now be'desc'ribedr It will be understood that various combinations-of degreesof angular rotation can be utilized, other: than tho'seherein:described.

The pulsing switch assembly As shown in Fig. 5, the pulsing switchassembly 24 includes the parallel normally open contact arms 92 and 93,which areconnected in series with the solenoid 91 (Fig. 7) and whicharesupported on a motor mounting plate 94 by a bracket 9'5. A gear 96 ismounted rotatably on the motor plate=94 'soas to mesh with=a gear 97which forms part of theg'ear train- 98 of a conventional motor-drivenantenna rotator 101 having a shaft-mounted drive pinion 101a. Thegear96' isprovided with. a camming: projection 99 which isadaptedto engage aportion 100 of the resilient switcharm 92 so as to displace the arm 92and bring it into contact-with arm 93 to close the solenoid circuit. Thegear ratios are so designed that gear 96 will rotate 360' in response to6 of rotation of the antenna structure.

The foregoing describes the major components of the control unit.

The transparent dial 75 is secured to the front plate 26, as by means ofscrews 102 and is provided with a series of suitable directional indiciamarks 103, preferably circumferentially spaced in increments of 6, inthis instance.

A molded knob 104 having a transparent flange portion 105 is fixedlysecured to the end of shaft 25 so as The knob is provided with a singleindex mark 106. The pointer 74 extends through .an opening 107 in thedial 75 so as to lie in between the dial and the flange 105 of knob 104.

One or more lights 108 may be secured to the front plate 26 toilluminate the dial 75.

Means are provided for limiting the rotation of knob 104 and selectorwheel 32 to a maximum of 360. This is accomplished by a latch element109 (Fig. 1) which is pivotally secured as at 110 to back plate 27. Onearm 111 of the element 109 extends rearwardly into an armate slot 112provided in plate 27, and the edges 113 of the slot limit the movementof the latch 109. Another arm 114 of the latch 109 extends forwardly ofplate 27 into the path of movement of a projection 115 (Fig. 2) which isprovided on wheel 32. It will be apparent that latch element 109 willarrest rotation of wheel 32 when ever projection 115 causes arm 111 toabut either edge 113 of slot 112.

The operation of the control unitv By reference to the schematic wiringdiagram shown in Fig. 7, the operation of the device may be more readilyunderstood.

When follower gear 53 and selector wheel 32 are in the position shown inFig. 2, the cam screw 56 maintains the switch arm 38 out of Contact withswitch arm 39. The power circuit through the primary winding oftransformer 19 is thus open and the rotator does not operate. Underthese conditions, the pointer 74 should be in registry with the indexmark 106 on knob 104.

When the knob 104 is rotated in either direction, the selector wheel 32will be rotated in the same direction a like degree. The contact arm 38will then be out of phase with screw 56 and the switch 37 will be closedcausing transformer 19 to be energized. The escapement assembly 23prevents follower gear 53 from rotating when wheel 32 is rotated.Depending upon the direction in which wheel 32 is rotated, eithercontact arm 41 will engage contact arm 65 on drum cover 64 and rotatethe cover clockwise (Fig. 4), or contact arm 40 will engage contact arm66 on drum 59 and rotate the drum counterclockwise.

The relative rotation between the drum 59 and cover 64 is translatedinto energization of torsion spring 60 which, through projection 67, is,impressed as a torque upon gem-53.

Assuming now that contact; arm 41. has engaged contact arm 65, thisserves. to. close a low voltage. circuit through the winding 116' of therotator motor and through a thermal. overload switch 118, which. is.provided; for protection of the circuit. The antenna rotator will. thenrotate in: one direction- The electrical connectionsare shown byterminals 15a, 15b, 15c and 15d. on. control unitter minal strip 14 andby terminals a, 120b,", 1200 and'120d' on rotator terminal strip 119..

During each. 6 rotation. of the; rotator; the .cam; gear 96 will rotatethrough one complete revolution and will momentarily close the switch92-93 to transmit an electrical impulse to solenoid. 9:1.v Theenergization of solenoid 91 will actuate the, escapement wheel, 69 inthe manner heretoforedescribed. For each: solenoid impulse, theescapement wheel 69 will permit the follower gear 53 to rotate 6.

As soon as the antenna rotator has energized the solenoid a sufiicientnumber of times, the follower gear 53 will again be in phase with theselector wheel 32 and the cam screw 56 will open switch 37 to interruptthe transformer circuit. The rotation of the antenna rotator will thencease. At this point the pointer 74 will again be in registry with theindex mark 106.

If the rotation of knob 104 is in the opposite direction, the contactarm 46 will engage contact arm 66 to establish a motor circuit throughreversing winding 117 so that the rotator motor would revolve in theopposite direction. The rotator would then continue its rotation, in themanner above-described, until the follower gear 53 was in phase withselector wheel 32.

When the control unit is installed, it may be tested by rotating knob104 to one limit of position and noting whether pointer 74 comes intoregistry with mark 106 during operation of the rotator. If it does not,the lever arm 79 of the escapement assembly may be manually manipulatedby means of finger 81 to bring the gear 53 into phase with wheel 32 andthereby bring pointer 74 into proper position. If the pointer registerswith index mark 106 in one limit of position of knob 104, the knobshould be rotated to its other limit of position to determine whetherthe pointer properly tracks the index mark. If it does not the lever armmay be manually manipulated as aforesaid to obtain the propersynchronization. As heretofore stated, the pointer 74 is frictionallysecured to the pointer gear 73 so that the pointer may be independentlyadjusted if necessary.

The antenna can be oriented with the directional markings 103 in amanner familiar to those skilled in the art.

It is to be understood that the forms of our invention, herewith shownand described, are to be taken as preferred examples of the same, andthat various changes in the shape, size and arrangement of parts may beresorted to, without departing from the spirit of our invention, or thescope of the subjoined claims.

Having thus described our invention, we claim:

1. In a control unit for an electrically-actuated rotator device, thecombination of a rotator-actuating circuit including a normally-closedrotator-actuating switch rotatably mounted on said unit, a movableswitch-opening member operatively engaging said switch, means for rotating said switch in either direction out of engagement with said memberto close said switch, a single torsion spring having one end thereofoperatively associated with said switch and having the other end thereofoperatively associated with said member, said spring being energized inresponse to rotation of said switch, and means responsive toenergization of said spring for moving said switchopening member in acorresponding direction to reengage said switch.

2. In a control unit for an electrically-actuated rotator device, thecombination of a rotator-actuating circuit ineluding a normally-closedrotator-actuating switch, a rotatable selector element supporting saidswitch for orbital movement, a follower member mounted for coaxialrotation relatively to said selector element, a switch-openingprojection provided on said member in the path of movement of saidswitch and normally engaging said switch, a torsion spring carried bysaid follower member, means on said selector element engageable witheither end of said spring to energize the same in response to rotationof said selector element relatively to said follower member, and meanson said follower member engaged by the other end of said spring to urgesaid member to rotate into switch-opening position.

3. A combination as defined in claim 2 wherein said torsion spring ispre-stressed, one end of said spring being secured to a first armmounted for coaxial rotation relatively to said element and said member,the other end References Cited in the file of this patent UNITED STATESPATENTS 2,090,812 Schmitt Aug. 24, 1937 2,340,174 Chance Jan. 25, 19442,436,068 Hegy Feb. 17, 1948 2,578,347 Gagnaire Dec. 11, 1951 2,680,223Hammett June 1, 1954 2,682,628 Jordan et al June 29, 1954 2,682,629Jordan et al June 29, 1954

